Cowling for aircraft motors



July 21, 1936. R. e. BREENE El AL.

COWLING FOR AIRCRAFT MOTORS Filed Oct, 24, 1929 3 Sheets-Sheet lB'essure I I F I I I I l I I I Pressure I I l I I I I I I I IN VEN TORSRo bari- Gi Bree ne. Car) [Greena {st/7s BBreZsFord. I

' TORN July 21, 19 R. G. BREENE ET AL 2,047,943 I COWLING FOR AIRCRAFTMOTORS Filed Oct. 24, 1929 3 Sheets-Sheet 2 INVENTOR5 Roberta Breere.Carl E Greene jmesfi. Brelsfori TTORN Y July 21, 1936. R. G. BREENE ETAL COWLING FOR AIRCRAFT MOTORS a sheets sheet 5 Filed Oct. 24, 1929INVENTORJ Robert 61. Breezes Carl ford.

BYM

Patented July 21, 1936 cownme FOB. AIRCRAFT MOTORS Robert G. Breene,Carl F. Greene, and James Brelsford, Dayton, Ohio Application October24', 1929, Serial No. 402,196

- scieims. (01. 244-31) (Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 0. G. 757).

This invention described herein may be manu- With the above and otherobjects in view, our factured and used by or for the Government forinvention .consists in the -novel construction and governmentalpurposes, without the payment to arrangement of parts which will behereinafter us of any royalty thereon.

The present invention relates generally to imnormal shape of thecowling. When the air striking the cylinders is unusually cold, as forinstance when the airplane is flying at a great altitude or is in a longdive, these closures may be practically closed against the cowling.

described, pointed out in our claims and illustrated stantiallyatmospheric pressure. From the point D, the curve goes below the lineA-A', indicating a suction area; that is to say a pressure belowatmospheric pressure. The curve crosses the axis again at point E, andterminates at the point F,

in the accompanying drawings in which 6 provements in the stream liningand cooling of Fig. 1 is a plan view of an airplane having a aircraftEngines anfd t1rlnoiige palrticularlty i;to the cowling mounted thereonin accordance with our coo ing 0 engines 0 e ype aving S a ionaryinvention. radially disposed aircooled cylinders at the nose Fig. 2 isa, curve obtained as the result of wind of Tt lllre filiselage.f th t td th tunnel tests showing approximately the location 10 e 0 ice 0 einven ion is 0 re uce e of the pressure and suction areas around thedrag of such aircraft without unduly diminishing fuselage of an airplanewhen it is in flight. the c olin effect on the engine ylinders. It Fig.3 is a view in perspective of the cowling has been found as a result ofwind tunnel tests shown mounted upon the engine nacelle of an onairplane fuselages that for a short distance airplane. 15 along the noseof the fuselage, there is formed Fig. 4 is a view in perspective showingthe cloan area of rather high pressure when the airplane sure means andvane arrangement. is in flight; that is to say, an air pressure moreFig. 5 is a front view of the engine cowling and or less above thenormal atmospheric pressure. Fig. 6 is a sectional view taken on theline 6-6 This is the natural result of the movement of the of Fig. 5. V20 igselaie thrgufhbthli aifnthwindttulnnel ttesits fur- Cogespondinglparfi: are designated by correer s ow a ac o e'lus escri e presspon 'ngnumeras t oughout the drawings. sure area there is a somewhat longersuction area. Referring now to Figs. 1 and 2, the numeral 2 By suctionarea is meant an area in which the I0 designates a typical airplanefuselage having p r i l w h normal atmospheric ,presa stationary radialcylinderair-cooled-engine of 25 sure. The invention consists in lprovision of conventional design mounted at the front thereof a Darticliform, disposition an curva ure 0 .in the usual manner. The engine llcarries a n in w n and a i n tive air guides or propeller l2 mounted onthe propeller shaft l3 of vases withtin saidfcgiwling. Theforliimgdigplgsitign theengine. A spinner H of conical form with its anan curva lire 0 e englne COW l1 1 a a a ex directed forward] is attachedto the rovantage of the stated conditions to provide an 211 h b, yadequate air flow over the engine cylinders and at Referring now t tcurve w 1 Mg. 2, th the same time reduce the drag effect which they linewhich equal to the length f the would otherwise impose, whereas theadjunctive gle aerodynamic structure of which the fuselage sti t.eswtzzzsgztizszrst that: e we of thereby increase the air velocity flowadjacent z fiz' iz g z i zg f gf gz i g g igi gz to the heat-radiatingfins of the engine cylinders. fine indicate pressure elow atmosphericThe As will be recognized by those skilled in the art, pressure curve isindicated at C D E This and as has been demonstrated in practice, theintended to mu tr te 1 40 ling air, which is separated from the outsidecurve 18 s q we Va ues only and is not intended to indicate any definiteair, is returned rearwardly and with little disturbnce thereofPreferably the air outlet at the units of pressure a Referring now tothe curve C, D, E, F, it will be rear end of the cowling is of smallereffective area than the air inlet at its forward end. noted thatthe-highest 18 at the point c 45 The invention is further characterizedby proat the extreme. 3 of the aerodynamic viding a cowling such ashereinbefore described stmqwre compnsmg w fuselage and engine havingmanually adjustable and radially extendcowhng' From 'pomt C thepressurerapidly ing closures for the air intake opening which drops P to wherethe curve crosses closure when in a closed position conforms to the theaxls A A at whlch pomt' the pressure is the area back of the point Ethus being a pressure area.

framework [5, which comprises essentially a front ring member l6 and arear-ring member I! concentrically arranged relative to the front ringwhich are screwed into within the pressure area C'D' than in itsrearward part member, is provided, the front ring member being attachedto the crank case of the engine by means of a series of radiallyextending lugs l8 provided lugs are provided on the ring member. Thesewith suitable openings for receiving bolts 19 tapped holes provided inthe crank case in'the usual manner as shown in Fig. 6 of the drawings.

The rear ring member His secured to the front end of the fuselage bymeans of a plurality of ra-' dially arranged angularly extending bracerods 20-suitably-secured to the ring member at their one ends as bywelding, the other ends of the said rods having flattened portions 2|provided with openings for passing bolts 22 therethrough which arescrewed into the fuselage, thereby establishing a substantially rigidanchorage at that point.

The frame work l5 further includes the use of plurality oflongitudinally extending supporting trusses 23 secured. at spaced points24 and 25 around the peripheries of the front andrear ring membersrespectively which aresoeshaped as to define approximately the contourof the cowling. The cowl plates forming the covering for the frameworkmay be divided into two or more similarly formed pieces 26, the forwardends of which are hook-shaped as at 21 to flt around and under theforward edged the front ring member It. From the foregoing,.it will beapparent that the cowl plates when mounted upon the framework aresecurely anchored at the forward end against displacement. Cowlfasteners 28 are attached along the forward end and the sides of thecowl plates and are so located as to be coincident with openingsprovided in attaching plates 29 fixedly mounted on the supportingtrusses 23.- The cowl fastenersv may be. of any conventional designwhich will securely hold the cowl plates against otherwise they forminvention. Itwill lies for the major part and is arranged in a mannersuch that the rear edge of the cowl be noted that the cowling 'ingextends partially within the suction area D'--E'; that is to say at apoint within the suction area and adjacent the pressure area. By po-.sitioning the'lntake opening of the cowling and the exhaust opening inthepressure and suction areas. respectively a better air flow isobtained both within and without the cowling.

The shape of the cowling which is of sub!- stantially ring form isimportant.' It is of sharper curvature or deeper camber in its forwardpart which is flatter, and its front edge is curved inward directly infront of air entrance opening for the the cylinder heads so as to definea relatively blunt-nose'entry for the structure as well as an cowlingwhich is of less effective area than the projected area of the engine,and is wholly contained within said area Just abaft of the .cowlingextends to the rear of the cylinders ,vided which are cylinders of theare operated the propeller, while the flatter rear part or nacelle,forming therewith a rearwardly facing narrow air outlet opening whichruns substantially continuously around the body. The individual cylinderexhaust pipes may project through this I opening as indicated. Suchcowling preferably converges slightly from its forward toward its rearend, but in any event forms, in conjunction with the external contour ofthe body covering lo, the characteristic shape of a single properlystreamlined body, or substantially so, the cowling thus virtually beinga forward continuation of the lines of the streamlined body contour andgiving rise to pressure and suction areas in the relation above referredto. The cowling provides a passage through it for the flow of airagainst and between the cylinder barrels and in order that the air maybe best utilized for abstracting the engine heat, air guiding ordeflecting means may be and preferably are provided for locallyincreasing the air velocity adjacent a plurality of radially arrangedvanes 32 are promounted upon the front ring member and positionedintermediate adjacent engine which are for the purpose of directing theair flow around the cylinders. A plurality of similarly constructeddeflecting vanes 33 mounted intermediate the cylinders and in line withthe front vanes are secured to the fuselage of the airplane, the purposeof which to complete the circulation of air around the rear of thecylinders; the rear vanes being formed with concave sides 34 to carrythe foregoing into eflect. These air deflectors. it may be pointed out,cooperate with the form of cowl above described, to 7 increase theheat-radiating properties of the engine, at the same time decreasing thedrag of the body and engine combination, and preferably the deflectingsurfaces 3 3 are of greater circumferential width than the intercylinderspaces in order not merely. to'increase the velocity flow of the coolingair near the cylinders or in contact with the fins but also to direct ittoward those portions of the cylinders which might otherwise tend tooverheat. 1

The engine temperature is controlled through the use of a system ofmanually controlled shutters disposed intermediate the propeller andenglue and comprise essentially a plurality of radially arrangedshutters 38 pivotally mounted as at points TI to the ring member. Theshutters through the use of a ring piece38 which is plvotally connectedto a ring member 39 attached to each shutter respectively as shown inshaft 4' which enters the pilot's cock pit. From the foregoingdescription, it willbe apparent that in the event ,that shaft 46 ismoved in the direction of the arrow 48, the ring piece 38 will berevolved in the directionof the arrow 49 to partiallyor wholly close theshutters, while a movement of the shaft 48 in the opposite directionwill effect an opening ofthe shutters. v While we have illustrated anddescribed th preferred form of construction for carrying our inventioninto effect, it is to be understood that variations and modificationsmay be made without departing from the spirit of our inventlofif,

to the cylinders. To this end, 20

It is also to be understood that the term body as used herein includesfuselages, nacelles, or other streamlined air-craft bodies at theforward end of which an engine and propeller are disposed.

We, therefore, do not wish to be limited to the precise detailsofconstruction set forth but desire to avail ourselves of such variationsand modifications as come within the scope of the appended claims.

Having thus described our invention, what we claim, as new and desire tosecure by Letters Patent is:

1. In aircraft, in combinatioma body, a stationary radial cylinderair-cooled engine having heat radiating fins on the engine cylinders,said engine being mounted at the forward end of said body, a. propellerdriven by and mounted forwardly of said engine, and means for increasingthe heat radiating properties of the engine and decreasing the drag ofthe body and engine combination comprising a cowl of substantially ringform within which the engine is completely enclosed, said cowlbeingshaped to provide a substantially unbroken forward continuation ofsaid body-and being curved relatively abruptly inwardly at its forwardend between the engine and the propeller to provide 'therebetween arelatively blunt-nose entry for said cowl and body combination; saidcowl throughout its rearward part being of less degree of curvature andextended rearwardly for some distance behind the engine and intosubstantially overlapping relation to .said body, said cowl being openin front and in back, the front endopening being intermediately locatedbetween the engine, and propeller and within the projecteddisc area ofthe engine, and

the rear' end opening being rearwardly faced and disposed at saidoverlap to extend substantially continuously around said body, and meanswithin the cow] organized to increase the velocity of flow locally ofthe cylinders and shaped to deflect the air in its passage through theintercylinder spaces toward those portions of the engine cylin-,

ders which might otherwise tend to overheat.

2. In aircraft, in combination, a body, a stationary radial cylinderair-cooled engine having heatradiating fins on the engine cylinders,said engine being mounted at the forward end of said body, a propellerdriven by and mounted forwardly of said engine, and means for increasingthe heat radiating properties of the engine and decreasing the-drag ofthe body and engine comstantially unbroken forward continuation of saidbody and being curved relatively abruptly 1nwardly at its forward endbetween the engine and the propeller to provide therebetween arelativelyblunt-nose entry for said cowl and body.

combination, said cowl throughout its rearward part being of less degreeof curvature and extended rearwardly for some distance behind the airdirecting surfaces intermediately located'with relation to the enginecylinders and shaped to direct the cooling air in its passage throughsaid cowl toward the rear portions of the engine cylinders, each saidsurface having a circumferential width exceeding that of its associatedintercylinder space.

3. In aircraft, in combination, a body, a stationary radial cylinderair-cooled engine having heat radiating flns on the engine cylinders,said engine being mounted at the forward end of said body, a propellerdriven by and mounted forwardly of said engine, and means for increasingthe heat radiating properties of the engine and decreasing the drag .ofthe body and engine combination comprising a cowl of substantially ring'form within which the engine is completely enclosed, said cowl beingshaped to provide a substantially unbroken forward continuation of saidbody and being curved relatively abruptly inwardly at its forward endbetween the engine and the propeller to provide therebetween arelatively blunt-nose entry for said cowl and body combination conduciveto a smooth external air flow, said cowl throughout its rearward partbeing of less degree of curvature and extended rcarwardly for somedistance behind the engine and into substantially overlapping relationto said body, said cowl being open in front and in back, the front endopening being intermediately located between the engine and thepropeller and within the projected disc area of the engine,- and therear end opening being rearwardly faced the engine cylinders, theair-after its passage rearwardly beyond said air-deflecting surfacesbeing discharged from said cowl through said outlet in a directionsubstantially parallel to the direc-- tion of the flow of air passingexternally over the cowl and body combination.

4. In aircraft, in combination a body, a stationary, radial cylinderair-cooled engine mounted at the forward end of said body, a propellerdriven by and mounted forwardly of said engine, and an annular cowlingsurrounding said engine and extended rearward of the cylinders to formwiththe body a single structure of substantially streamlined contour,the cowling at its forward v end being curved relatively abruptly inwardin bination' comprising a cowl of substantially ring form within whichthe engine is completely enclosed,'said cowl being shaped to provide asubfront of the engine cylinders and behind the propeller to provide ablunt entry for the aircraft, and an air entrance located wholly withinthe projected disc area of the engine, said cowling toward its rearwardend being slightly convergent inwardly behind said cylinders, saidconvergent part forming a narrow annular air outlet located at theforward end of said body andextending substantially continuously aroundthe same.

, ROBERT G. BREENE.

CARL F. GREENE. JAMES B. BRELSFORD.

